diff --git a/async.c b/async.c
index ecdaf15..85cc641 100644
--- a/async.c
+++ b/async.c
@@ -35,10 +35,10 @@
 struct QEMUBH {
     QEMUBHFunc *cb;
     void *opaque;
-    int scheduled;
-    int idle;
-    int deleted;
     QEMUBH *next;
+    bool scheduled;
+    bool idle;
+    bool deleted;
 };
 
 QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)